Anthraquinone dyes have been widely used to dye fabrics, such as cotton, polyester, acrylic, wool, cellulose acetate, nylon, and the like, due to their excellent light fastness, uniform leveling, dye bath stability, and shade brilliancy. Anthraquinones are also well known for use as coloring agents for providing coloration to oils, drugs, cosmetic products, paper, rubber, printing inks, plastics, coatings, leather, waxes, and detergents. These types of anthraquinone dyes may be classified as acid dyes, disperse dyes, vat dyes, metallizable dyes, direct dyes, solvent dyes, basic dyes, reactive dyes, and the like.
Many violet anthraquinone dyes are known. Commercially available examples of violet anthraquinone dyes include Acid Violet 39, Acid Violet 41, Acid Violet 42, Acid Violet 43, Acid Violet 48, Acid Violet 51, Acid Violet 34, Acid Violet 47, Acid Violet 109, Acid Violet 126, Basic Violet 24, Basic Violet 25, Disperse Violet 1, Disperse Violet 4, Disperse Violet 26, Disperse Violet 27, Disperse Violet 28, Disperse Violet 57, Solvent Violet 11, Solvent Violet 13, Solvent Violet 14, Solvent Violet 26, Solvent Violet 28, Solvent Violet 31, Solvent Violet 36, Solvent Violet 37, Solvent Violet 38, Solvent Violet 48, Solvent Violet 59, Solvent Violet 60, Vat Violet 13, Vat Violet 15, Vat Violet 16. However, these violet anthraquinone dyes are not polymeric in nature, and they tend to exhibit stability, gelling and precipitation challenges when incorporated into other formulations, such as detergent formulations and other consumer cleaning products. Furthermore, the water soluble violet anthraquinone dyes, such as acid violet dyes, are known to cause staining to textile substrates (such as fabrics), skin, and other surfaces. Thus, they are not suitable for use in applications where non-staining colorants are desired, such as in washable markers and paints and in cleaning formulations such as laundry detergents and fabric softeners.
Furthermore, these anthraquinone violet dyes are generally provided in powder form which is often difficult to handle. While these dyes may be made into liquid form by dissolving the dye in water or organic liquid, the solubility of such liquid dyes is low and the resulting liquid dye solutions tend to have very low color strength. Color strength, or color value, is determined using a modified version of AATCC Test Method 182-2000 wherein the color value is determined and calculated on the absorbance of a 1 gram per liter through a one centimeter cell length of the colorant, in the appropriate solvent, by UV-vis spectroscopy.
Attempts by others to make violet anthraquinone colorants include U.S. Pat. No. 3,192,117 to Kaiser et al., which provides some examples of violet anthraquinone compositions useful as hair dyes. These colorants exhibit good dyeing ability when they are incorporated into the dyeing creams or pastes. Similar to the acid dyes described above, these compositions cause staining to the substances to which they are applied. In this instance, it is desirable to use staining anthraquinone colorants for dyeing human hair. Thus, the colorants taught by Kaiser et al. are not polymeric in nature, and they are not non-staining. Additionally, the colorants taught by Kaiser et al. preferably contain two nitrogen-containing primary groups on the anthraquinone radical.
U.S. Pat. Nos. 1,881,752 and 2,014,810 to Lodge et al., U.S. Pat. No. 2,117,569 to Peter and U.S. Pat. No. 2,580,190 to Peter et al. described several anthraquinone dyestuffs, including anthraquinone violet dyes. U.S. Pat. No. 3,689,510 to Kolliker et al. describes a class of water soluble anthraquinone dyes with an —O—COOR group in at least one β-position. These dyes may be used for dyeing synthetic polyester fibers and exhibit good fastness to light and sublimation. U.S. Pat. No. 3,715,373 to Andrews disclosed a process to prepare 1,4-diamino-2-alkoxy or phenoxy anthraquinone dyestuffs from an acyl-substituted 1,4-diamino-2-haloanthraquinone in a inert solvent. David 0. Ukponmwan and et al. in J. Chem. Eng. Data 1984, Vol. 29, pp. 482-483 and 1987, Vol. 32, pp 282-284, synthesized a series of 1-amino-4-(arylamino)anthraquinone 2-ether and 1,4-Bis(arylamino)-2-(aryloxy)anthraquinone dyes used for dyeing synthetic polymer fibers. However, these references teach the manufacture of small molecule anthraquinone dyes. Thus, no teaching or fair suggestion of polymeric versions of such dyestuffs is known, nor is it taught or fairly suggested that these colorants could be used for coloring consumer products.
Great Britain Patent No. 859,283 teaches water soluble anthraquinone dyestuffs useful for dyeing fibers, leather and paper. The water solubility is introduced by sulfonic acid, sulfuric, or carboxylic acid groups on the anthraquinone dye molecule. These are small molecules which contain triazine units and ionic groups to make them water soluble. These dyes are also generally blue in nature.
Other anthraquinone colorants, such as 1,4-disubstituted aliphatic aminoanthraquinones, are disclosed in U.S. Pat. No. 4,846,846 to Rekers et al. wherein anthraquinones were prepared from a mixture of quinizarin, leucoquinizarin, and amine in water followed by various purification procedures. The preferred amines are sec-alkyl primary amines with terminal reactive groups, such as —OH, —NH2, or —SH, on the end of the amine moiety. These anthraquinone colorants are used to color polyurethane resins, particularly foams.
U.S. Pat. No. 4,137,243 to Farmer discloses polymeric anthraquinone colorants with terminal amino groups from leucoquinizarin and polymeric diamines. The leucoquinizarin can be generated in-situ by reduction of quinizarin with sodium hydrosulfite. The polymeric aminoanthraquinone colorants prepared according to the above patent processes tend to contain high levels of impurities, such that further purification is needed to obtain higher purity anthraquinone colorants. Purification of low melting or liquid water-soluble anthraquinone colorants usually involves time consuming extraction and washing procedures that often require organic solvents, which generally are not environmentally friendly. Additionally, these solvents are typically not suitable for use in many consumer product applications and complete removal is required. The organic solvents are often expensive and generate additional waste during production of the anthraquinone colorants. Furthermore, some of the impurities in these anthraquinone colorants are often difficult to filter and generally cause dull color, shade shift, and staining.
U.S. Pat. Nos. 4,224,228 and 4,244,691 to Adam disclose water soluble anthraquinone dyes in the form of free acid having one or more —SO3H group on the anthraquinone conjugated system. These anthraquinone dyes are used for dyeing or printing textile materials, such as natural and synthetic polyamide fibers, and exhibit good dye uptake and fastness to wet-processing. Optionally, these anthraquinone dyes have fiber-reactive groups, such as acryloyl, vinylsulfonyl, chloroacetyl, fluorotriazinyl radicals, and bromoacryloyl groups.
U.S. Pat. No. 6,022,944 to Weaver et al. discloses colored anthraquinone or condensed anthraquinone compounds with one or more sulfonamido linkages and poly(oxyalkylene) moieties. These colorants exhibit improved water dispersibility and compatibility with other organic compounds. However, the process to make these colorants involves adding one or more —SO2Cl groups on the conjugated rings, which is difficult and involves hard-to-handle reagents.
U.S. Pat. No. 6,593,483 to Xia describes a polymeric blue anthraquinone colorant, wherein a poly(oxyalkylene) chain is attached to the 1-position, or/and the 4-position through aromatic amino group(s) on an anthraquinone backbone. U.S. Pat. No. 6,635,350 to Connor et al. discloses a polymeric red anthraquinone colorant, where at least one poly(oxyalkylene) chain is attached to the 1-position, as well as at least one poly(oxyalkylene) chain is attached to either the 5-position or the 8-position of an anthraquinone backbone.
Thus, there is a need for a polymeric violet anthraquinone colorant that exhibits excellent light and pH stability, that is compatible with other materials, and that is suitable for use in coloring various consumer products. The colorant is also desirably non-staining and water soluble with bright shades.
Accordingly, one object of this invention is to provide a polymeric violet anthraquinone colorant, preferably a 1,4-diamino-2-polyalkyleneoxy violet anthraquinone colorant, that exhibits bright shades, high pH stability, good light fastness and compatibility with other materials. Another object of this invention is to provide methods to make such anthraquinone colorants. A further object of this invention is to use these inventive colorants for coloration of consumer products, such as liquid and solid laundry detergents and liquid fabric softeners.